Why Are Sunflowers Yellow? (And What Other Colors Can They Be)

Sunflowers, with their blazing yellow petals and deep dark centers, are one of the most unique flowers in the world. Considering the stunning resemblance they have to our life-giving sun, it’s no wonder that they’re named in its likeness. But most people don’t stop to think about why sunflowers are yellow. If you’re one of those who do, fret not. We’ve scoured the web to find the answer to that question, plus so much more about this beautiful plant. 

Sunflowers, or rather their petals, look yellow to us because yellow is the only wavelength of light that doesn't get absorbed by the flower, and instead, gets reflected back to our eyes. That dominant wavelength of a sunflower’s petals (which is in most cases yellow) is determined by the presence of flavonoids, the chemicals responsible for giving it it’s pigment.  

This is a lot to take in, we know. Keep reading; the next paragraphs will break down more about how we perceive sunflowers to be yellow, as well as the chemicals within it that produce the color.

Why Are Sunflowers Yellow 

To fully understand why sunflowers are yellow, you first need to understand a little about color science, also known as colorimetry. Colors are the visual portion of the electromagnetic spectrum. And every color has a corresponding wavelength. There are six in all: white (all the colors), black (the absence of color) red, green, blue, and yellow, which can be mixed to varying degrees and create more colors.

An object’s genetic makeup is what determines how it interacts with wavelengths. In other words, it determines whether it absorbs certain wavelengths and reflect others. Those factors that determine the colors that we see. So, if a sunflower’s petals are yellow it’s because the yellow wavelength is being reflected back into our eyes, while all others are being absorbed.

As for why the biological makeup of a sunflower reflects yellow wavelengths, instead of other colors, that answer is simple. For this species of flora, yellow happened to be the color that was the most attractive to the bees that pollinate it.

Interestingly enough, insects don't see the color of sunflowers as we do. Their vision includes different sections of the spectrum than ours. Here's an interesting video that shows how flowers look to insects -

Are All Sunflowers Yellow?

Not all sunflowers are yellow. In fact, there are several different species of sunflowers that come in a range of beautiful colors. Everything from red to pink, purple, and even black! Most are the result of cross-breeding by botanists, though some occur naturally.

Red sunflowers

Ms. Mars Sunflower is a deep red sunflower that some compare to flames.

Black sunflowers

And Mammoth Black Sunflowers are aptly-titled stunning, black flowers with black centers and petals.

Pink Sunflowers

The Skywalker Sunflower has bright, pink petals and golden tips.

Purple Sunflowers

We have found photos of purple sunflowers but we couldn't track down the name of this variety or even confirm if it's genuine. It certainly is pretty! You can even buy seeds for these beauties on Amazon -

 

Can Sunflowers Have More Than One Color?

Some sunflowers are multi-colored, as in the case with the Skywalker sunflower and a few other species.

What Color Are The Centers Of Sunflowers?

No matter what color the petals of a sunflower are, their centers are usually always dark. The most common center is brown, while some are black.

The Beauty of Sunflowers

We hope that you enjoyed learning more about sunflowers. To reiterate: most sunflowers are yellow because of their biological makeup. Nature deemed yellow the best color to ensure their continued survival. That’s why they’re packed with flavonoids, known as carotenoids, that are responsible for which wavelengths get absorbed (most other colors), and which get reflected (yellow). Sometimes, the colors of sunflowers can be manipulated which results in some of the beautiful, unique strains above.